let a = {
    name: 'lee',
    age: 18
}

let b = a;

console.log(a.name);  //第一个console ，lee

b.name = 'son';

console.log(a.name);  //第二个console ，son

console.log(b.name);  //第三个console ，son

//引用类型，存在堆里